The present invention relates to the provision of firm stable three-dimensional expanded structures, that are capable of being collapsed down to compact bundles.
There are many times when one wishes to have an enclosure at a remote site and, rather that transport it to such site, one transports it in some collapsed form. Thus, a tent is folded up, transported and erected where needed. A fabric tent, however, has no rigidity and it is therefore necessary to utilize tent poles, pegs, and rope to give the tent some degree of rigidity. Further, it must be set on a reasonably firm sub-surface.
Pneumatically inflatable enclosures are another option for such a portable enclosure, but again substantial preparation is required.
The present invention provides reasonably rigid three dimensional enclosures that may be readily collapsed and expanded. These structures are made up of units which are comprised of facets that are connected by pleats or hinges. This invention has many desirable characteristics:
First, they fold down to a very compact bundle. Given the size of the structure's basic facet, the collapsed structure will essentially consist of a stack whose area is the size of that facet and whose height is the sum of the thicknesses of all the facets in the structure.
Second, it is possible to construct a wide variety of shapes and forms utilizing this method. Illustrated herein are such shapes as planes, cylindrical sections, cones, tent shapes, and doubly curved surfaces. This variety of forms allows for many different uses.
Third, many of the forms and shapes that can be made may be constructed from a single flat sheet of material that is scored or pleated. Because only a single flat sheet is required, many low cost manufacturing techniques may be employed, such as stamping, simple molds, etc.
Fourth, this method allows for utilizing materials of finite thickness. Plastics, wood, metal and other rigid materials may be employed for making structures that require more permanance and rigidity.